Section-insulator for trolley-roads.



No. 835,909. PATENTED NOV. 13,1906. 0, M. MEANS.

SECTIONv INSULATOR FOR TROLLEYv ROADS.

APPLICATION FILED APR. 9', 1906.

UNITED STATES PATENT OFFICE.

CHARLES M. MEANS, OF FUNXSUTAWNEY, PENNSYLVANIA, ASSIGNOR .TO H. W. JOHNS-MANVILLE COMPANY, A CORPORATION OF NEW YORK.

Specification of Letters Patent.

Patented Nov. 13, 1906.

Application filed April 9, 1906. Serial No. 310,690. I

To all whom it may concern:

Be it known that 1, CHARLES M. MEANs, a citizen of the United States of America, and a resident of Punxsutawney, county of J eflerson, State of Pennsylvania, have invented certain new and useful Improvements in Section-Insulators for Trolley-Roads, of which the following is a specification.

My invention relates to section-insulators for electric trolley-roads in general; and it more specifically consists of an improved sec tion-insulator for use in mines and tunnels.

The ordinary section-insulator used on surface trolley-roads has its insulating portion formed of wood or fiber and exposed. When such an apparatus is used in a mine or tunnel, the constant dripping of water on it ,soon saturates it, destroys its insulating properties, and then disintegrates the whole apparatus. These section-insulators are also generally made of such form that when any defect in the insulation occurs the current leaks to the adjoining section rather than to the ground. This is a source of danger in mines, as the wires are strung only-four or five feet above the rails and men are required to work along and under thiswire atall times. In minework the section-insulator must be attached to the rocky roof of the tunnel. This it is diflicult to do with any of the standard forms of section-insulator. Standard practice in mining requires the fre uent insertion of section-insulators in trolley-wires after they have been strung. It is difficult to do this with the ordinary form of section-insulator without having the Wire slack. Such slackening of the wire is particularly objectionable in minework, as the wire is only a few inches below the tunnel-roof, and if slackened is ushed up into contact therewith by the troley-wheel. Ihave invented a form of sectioninsulator which avoids all these difliculties and has other advantages hereinafter to be pointed out. The best form of apparatus embodying my invention at present known to me is illustrated in the accompanying sheet of drawings, in which- Figure 1 is a side elevation of my improved section-insulator. Fig. 2 is a plan view, and Fig. 3 a detail view in section. Fig. 4 is a detail cross-section taken on jline 4 4 of Fig. 1 looking in the direction of the arrow.

Throughout the drawings like referencefigures indicate like parts.

1 is the base-plate or bed-plate, which may be made of malleable cast-iron. From this are suspended aseries of insulation-bells 2 2 by means of screw-bolts 3 3 and washers 4 4, &c. In each of these bells is forced a mass of molded mica or other molded insulation, (shown at 5 in Fig. 3.) This incloses and retains in place a screw-b olt 6, which is screwed into a socket in the upper portion of one of I nected to the clamp in the well-known manner.

13 is a hole through which a bolt or other convenient fastening means may be passed in order to attach the section-insulator to the roof of the tunnel or any convenient overhead support. g

In operating my invention the wire-clam s are preferably placed over the wire when -t e latter is in position, and the setscrews 12 12 are screwed down, so as to retain the wire in.

its position. The wire may then be out between the two olamps7 7, thus insulating the two sections of the trolley-Wire. When the progress of the minework renders it desirable to take out the section-insulator, the wire can be spliced by using a short splicingsleeve and the insulator inserted at another point farther down the tunnel or heading. The air-gap between the adjacent ends of the wire-clamps being slightly less than the airgap between said clamp and the insulatin be 1, any arc caused by a rapidly-passing tro lley-wheel will not jump to the adjacent insulator-bell, and so there is no tendency of the arc to melt and destroy the molded insulating material. The molded insulating material is entirely protected from the action of drip ing water, and if the moisture in the air shou d deposit a conducting-film 0n the under side of the molded insulating material any current which thus leaked away would be immediately conducted by the foundation-plate 1 to the mine-roof instead of leaking across to the other section of the wire and charging the same, to the danger of men who were worlging along the advaDOQ Section. The parts are easily assembled or taken down and replaced if any be broken or damaged. 'Each clamp having two supports and each'sup'port being embedded in the molded insulating material in a se arate bell, a much greater resistance is offere to any force tending to twist the clamp than is the case with prior constructions; Where such hangers have been supported from a single bell where the clamp has but one support embedded in molded material, a twisting force easily turns they support in its socket and breaks it free m h i urmimd ng molde material and begins the rapid destruction ofthe entire dev ce. V

The, advantages, of my invention comprise its imperviousness to the action of m is ur eing comp sed en e y of tal and molded insulation, the, protection of the, in ulating mat r a f m Water as far, as pos:

, sible, the ease of its application to a wire already strung, and the avoidance of, any ne: cessity for cutting out any considerable, section of said wire, with the result that the same can be easily s liced when thesection: insulator, is remove and other features Of novelty hereinbeforereferred to. l

Itis evident, of course, that various changes could be made in the details of construction shown and described without departing. from the spirit and scope of my invention so long asthe essential principles of operation hereinbefore referred to be preserved in Who e r n art- Having therefore described my invention, ;-c a m ating material in each of said bells, and two 1;. A section-insulator for electric. trolleyroads wh ch comprises 1n combmatlon a 3. A section-insulator for electric trolleyv.

roads which comprises in combination a main frame, and a pairof wire-clamps su ported thereby and insulated one from t e other, each of said clamps having a grooved channel in its side for reception of the trolley-wire, the upper portion of each channel beingv provided With set-screws and theunder portion with a horizontally-projecting li 4. A section-insulator for electric trol 6y? roads. which comprises in combination a metal bedspiece, a series of metalbells deending therefrom, a body of molded insuating material in, each of said bells, and two wire-clamps arranged in line and havin sup: ports embedded in said molded insu ,ating material, said; clamps having their inner ends separated one from another by a short air. gap, but separated from the nearest bell by a greater air-gap. I Signed at Punxsutawney, this 31st day of'March, 1906.

CHARLES M .MsA'N 3 Pennsylvania,

Witnesses:

F, L. NEEE, CnAs. H. JENKs. 

